Eosinophilic Bronchopneumopathy in Dogs

Resumo

Background: The eosinophilic bronchopneumopathy (EBP) is characterized by pulmonary infiltration with eosinophils. The etiology of canine EBP remains unclear, although hypersensitivity to aeroallergens is suspected. Dogs affected are usually young. The persistent cough is the most common clinical sign, often associated with respiratory difficulty and exercise intolerance. The diagnosis is based on signalment, radiographic and bronchoscopic findings, and the tissue eosiphilic infiltration demonstrated by cytology of bronchoalveolar lavage (BAL). No reports were found in Brazil. The aim of this paper is report four cases of canine BPE, with emphasis on clinical aspects, diagnosis and therapy.
Cases: Case 1. A 18-month-old female dog with 12 kg of body weight was presented for consultation with a 60-day history of cough, inappetence and weariness. It presented cough and tachypnea. The complementary exams demonstrated peripheral eosinophilia, bronchointersticial pulmonary pattern on radiography, moderate amount of mucus on bronchoscopy and
tissue eosinophilis infiltration on the BAL. The treatment was based on steroids, with improvement of clinical signs. Case 2. A 24-month-old female dog with 16 kg of body weight was presented for consultation with one-year history of cough, inappetence and lethargy. It presented only cough, and in complementary exams showed transitory peripheral eosinophilia, bronchointersticial pattern on radiography and predominantly eosinophilic inflammation on citology of BAL. The therapy was based on steroids, with improvement followed by worsening of signs, with need of readjustment of doses. Case 3. A 8-year-old male dog with 6.2 kg of body weight was presented for consultation with 3-weeks history of productive cough,vomiting and weight loss. The complementary exams showed peripheral eosinophilia, bronchointersticial pulmonary pattern
on radiography and eosinophils infiltration on cytology of BAL. It was used steroids as therapy, with improvement of signs. Case 4. A 2-month-old female dog with 2.8 kg of body weight was presented for consultation with 3-days history of cough, nasal discharge and inappetence. It presented severe expiratory dyspnoea, tachypnea, harsh cough, lung crackles on auscultation and lethargy. The complementary exams demonstrated leukocytosis by peripheral eosinophilia and neutrophilia, bronchointersticial and alveolar pulmonar radiographic pattern. The therapy was started with steroids, febendazole and antibiotics. Tracheal swab was obtained and it showed eosinophilic inflammation on cytology. After 20-days treatment, the signs improved. Maintenance therapy was performed with steroids.
Discussion: The EBP is usually reported in young patients, as described in three cases. The cough showed predominant clinically, associated with lethargy and inappetence in half of cases, as well as with dyspnea and weariness. The peripheral eosinophilia was observed in all patients, although transient in one of them, not being mandatory for the diagnosis.
Despite there are not a specific radiographic pattern to the diagnosis, the bronchointersticial pattern was common to the four animals, with worsening of the radiographic findings possibly related to worsening clinical findings. The definitive diagnosis made through identification of eosinophilic inflammatory infiltration by bronchoalveolar lavage (BAL). Steroid
therapy proved to be effective in the four cases.
Keywords: eosinophils, bronchus, lung parenchyma, dog.